4 Multiplexers may be stacked to accommodate up to 16 RS232 instruments when used with the D100S * Housing in terbland plastic (ASA + polycarbonate) * Polyurethane clip-on feet * Polycarbonate front plate and anodized aluminum back plate * Degree of IP protection (according to IEC529): IP50 * Weight 1 lb. 1 oz (.5 kg) * Working temperature +5°C to +40°C; storage temperature -20° to +60°C